1. Field of the Invention
The present invention relates to a lamp and, more particularly, to a lamp providing a self-heat-dissipating function.
2. Description of the Related Art
FIG. 1 shows a conventional lamp device 9 including a housing 91, a light emitter 92, a heat sink 93 and a fan 94. The housing 91 has an end forming a light-transparent portion 911 and another end forming an electrically connected portion 912. The housing 91 has an air inlet portion 913 and an air outlet portion 914 in the wall thereof. The light emitter 92, heat sink 93, and fan 94 are mounted in the housing 91, with the light emitter 92 coupled to the heat sink 93. The heat sink 93 has a side away from the light emitter 92 forming a plurality of fins 931 to define a compartment 932. The fan 94 is mounted in the compartment 932.
In use, the electrically connected portion 912 is coupled to a socket on a wall, a ceiling or a table (not illustrated) for being supplied with electricity so that the light emitter 92 can emit light passing through the light-transparent portion 911 to the environment. Besides, while the light emitter 92 is supplied with electricity generates undesired heat, air is drawn into an interior of the housing from an exterior thereof to form airflow “A” via the air inlet portion 913, passes through the gaps between any two adjacent fins 931, and then is exhausted back to the exterior via the air outlet portion 914. Thereby, through the heat conducting effect of fins 931 of the heat sink 93 cooperating with the movement of the fan 94, the undesired heat is transferred to the environment by the air currents. Consequently, the conventional lamp device provides a heat-dissipating function and, thus, the life of the conventional lamp device is longer than those of lamps without a heat-dissipating function.
Referring again to FIG. 1, although heat-dissipating function for the light emitter 92 can be provided by the heat sink 93 and the fan 94, a part of the airflow
“A”, designated as “a”, easily flows back to the air inlet portion 913 through the gaps between any two adjacent fins 931 after the airflow “A” being drawn into the compartment 932 by the fan 94 through the air inlet portion 913. Accordingly, the undesired heat can't be transmitted to the environment by the airflow “A” through the air outlet portion 914, and the airflow “a” passing through an end of each fin 931 adjacent to the air inlet portion 913 may cause turbulence with airflow “A” newly drawn through the air inlet portion 913. As a result, the heat dissipating efficiency of the heat sink 93 and the fan 94 is reduced and life of the light emitter 92 of the lamp 9 can not be extended effectively.